1. The problem statement, all variables and given/known data good afternoon, I am a problem with the E cross B drift velocity calculus from a charged particle. At first, an eletron is submitted a uniform magnetic field and have a circular trajetory. After, appear a uniform eletric field that create a drift velocity. The equations are: m dv/dt = qE + qv X B. Taking v constant or the mean aceleration zero, arrive the equation: v = (E X B)/B^2 But I don't understand why the v is constant or mean aceleration is zero. Anyone can help me?